Salami slicing Attacks

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What's salami slicing attacks?

Salami slicing refers to a series of many small actions, often performed by clandestine means, that as an accumulated whole produces a much larger action or result that would be difficult or unlawful to perform all at once. The term is typically used pejoratively. Although salami slicing is often used to carry out illegal activities, it is only a strategy for gaining an advantage over time by accumulating it in small increments, so it can be used in perfectly legal ways as well.

In information security, a salami attack is a series of minor attacks that together results in a larger attack. Computers are ideally suited to automating this type of attack.

Salami slicingHow to cheat water

meter

Salami slicingHow to cheat water meter

Rounding attacks

Rounding attacks

Rounding attacks

Rounding attacksEx1: Internet banking

Rounding attacksEx1: Internet banking

Rounding attacksEx1: Internet banking

Rounding attacks

Round(0.005, 2)=0.01 USD = 1 cent100 * (105.60 VND -> 0.01 USD) => 10,560.00 VND = 1.00 USD

Rounding attacksEx2: Petrol station

Rounding attacksEx2: Petrol station

22,200.00 VNĐ --> 1 litre200 VNĐ --> 0.009009009...

Round(0.00909, 2)=0.01 litre100 * (200 VND -> 0.01 lire) => 20,000.00 VND = 1 litre

Rounding attacksEx2: Petrol station

22,200.00 VNĐ --> 1 litre50,000.00 VNĐ --> 2.2522522522...

Round(2.252252, 2)=2.25 litre

Rounding attacksEx2: Petrol station

In Viet Nam, Petrol station uses round down/ truncate function. That means you guys always lose :)

Deposit accountEx 3

You have 100$, you deposit 100$ --> 1.2$/monthYou deposit 42 cents --> 0.00504$/monthRound(0.00504,2) = 0.01$ = 1 cent/month

You should share 100$ to 238 accounts (42 cents per account). After one month, You will get 238 x 0.01$ = 2.38$ :)

References

1.Salami attack at Asia Commercial Bank

http://www.vnsecurity.net/2008/05/salami-attack-at-asia-commercial-bank/

2. Adrian Furtuna - Practical exploitation of rounding vulnerabilities in internet banking applications

http://2013.zeronights.org/materials

3. Is Your Online Bank Vulnerable To Currency Rounding Attacks

http://blog.acrossecurity.com/2012/01/is-your-online-bank-vulnerable-to.html

4. http://en.wikipedia.org/wiki/Rounding

Questions?